US President Donald Trump launched a fresh attack on the news media Sunday by tweeting a video - bizarre even by his standards - showing him knocking down and beating a professional wrestling "villain" whose face had been replaced by a CNN logo.

The 10-year-old video, hailing back to Trump's days as a guest celebrity at pro-wrestling events, came after a week in which his unrestrained Twitter attacks on two MSNBC talk show hosts drew widespread condemnation from members of both political parties.

The latest tweet was immediately condemned by journalists, who said Trump seemed to be promoting violence against the media, while a Republican lawmaker said the president was trying to "weaponise distrust" through his postings.

But administration officials insisted Trump has a right to respond to critical coverage.

In the 28-second video, Trump, in a suit and tie, is seen knocking down another man in a suit who is standing next to a wrestling ring. Trump repeatedly pummels the fallen man, whose face is covered by the CNN logo. A fake CNN logo then appears on the screen reading "FNN: Fraud News Network."

A longer version of the video online shows that the man being beaten was World Wrestling Entertainment (WWE) owner-promoter Vince McMahon, a friend of Trump's. In that version, Trump also gets in the ring to shave McMahon's head as part of the "The Battle of the Billionaires" at the WrestleMania 23 event.

McMahon was present at the White House in February to pose smilingly with the president when his wife Linda McMahon - herself a former WWE executive - was sworn in as Trump's Small Business Administration chief.

Trump has recently stepped up his attacks on the news media. Besides the crude attack on MSNBC co-hosts Joe Scarborough and Mika Brzezinski - he called her "low I.Q." and said he had seen her bleeding after a facelift - he has also specifically bashed outlets including CNN, NBC, the Washington Post and the New York Times.

Amid a torrent of criticism over his attack on Brzezinski, Trump doubled down Saturday, tweeting: "My use of social media is not Presidential - it's MODERN DAY PRESIDENTIAL. Make America Great Again!"

With Trump's tweets coming just weeks after a mass shooting at a congressional baseball practice, reporters on Thursday asked White House spokeswoman Sarah Huckabee Sanders whether his rhetoric might be promoting violence.

She replied: "The president in no way, form or fashion has ever promoted or encouraged violence. If anything, quite the contrary."

But the wrestling video prompted a wave of new recriminations.

"It is a sad day when the president of the United States encourages violence against reporters," CNN said in a statement. "Clearly, Sarah Huckabee Sanders lied when she said the president had never done so."

My use of social media is not Presidential - it’s MODERN DAY PRESIDENTIAL. Make America Great Again!

CNN went on to suggest that instead of engaging in "juvenile behavior far below the dignity of his office," Trump should be focusing on issues like health care, tensions with North Korea and his upcoming trip to Germany for a G-20 summit and his first meeting with Russian President Vladimir Putin.

A White House official, homeland security adviser Thomas Bossert, defended Trump's video and said it demonstrated the president's "genuine ability to communicate to the people".

"I think that no one would perceive that as a threat," he said on ABC. "I hope they don't. I do think that he's beaten up in a way on cable platforms that he has a right to respond."

But Republican Senator Ben Sasse rejected that argument, saying on CNN that while a politician has a right to complain about bad coverage, there is a difference between that and "trying to weaponise distrust".

Meanwhile, several journalists said they feared Trump was stirring up anti-media violence.

Annie Lowrey, a former New York Times reporter now with The Atlantic magazine, tweeted: "In seriousness, I am terrified that a journalist - perhaps one of the many political reporters I know and love - is going to end up dead."